This invention relates to a lightweight shaft and methods of making the shaft and particularly relates to a lightweight shaft which forms a portion of a golf club and to methods of making the lightweight shaft for a golf club.
Golf clubs typically include a club head secured to a tip end of a club shaft and a hand grip assembled at a butt end of the shaft. The butt end of the shaft is formed with a uniform diameter of a first prescribed axial length which is larger than a uniform diameter of the tip end of a second prescribed axial length. A shaft of this type is referred as having a parallel butt and a parallel tip. The portion of the shaft which extends between the butt end and the tip end thereof is usually tapered from the larger diameter at the butt end to the smaller diameter of the tip end. The butt end and the tip end of the shaft could also be tapered or straight with a uniform diameter as noted above, or one could be tapered and the other straight.
In playing the game of golf, a golfer swings the club and aims the head thereof toward a golf ball which is located, for example, on a ground level surface. Ideally, when the club head strikes the ball, the ball is directed in a long trajectory toward, and on line with, an associated hole-like cup located on a fine grass surface.
Many years ago, shafts for golf clubs were made from wood such as, for example, hickory which was suitable for the bending and twisting to which the club was subjected when swung by the golfer. However, the use of wood for the shafts influenced the manner in which the golfer had to swing the club. Later, clubs with metal shafts, such as steel shafts, were developed and evolved into a highly successful product which enhanced the golfers playing of the game. In recent years, clubs with non-metallic shafts have been developed and provide a viable and popular option to the use of the metal shafts. The non-metallic shafts are typically made from blended layers of fiber reinforced polymer matrix composites such as, for example, graphite fibers carried in a prescribed pattern within an epoxy matrix.
There are several factors which are considered when designing a golf club to enhance the playing of the game. Perhaps the most important factor is the weight of the shaft. One of the parameters which is considered in the use of a golf club is the "swing weight" of the club. The swing weight parameter represents generally the weight of the club as it is being swung and is related to the overall weight and the weight distribution in the club. Clubs are classified in several principal grades, and several sub grades within each principal grade, based on the swing weight of the clubs. Generally, the lighter weight clubs are used by the weaker hitters while the heavier weight clubs are used by the stronger hitters such as the low-handicap and professional golfers.
The development of the composite shaft resulted in a shaft which is lighter in weight than the steel shaft and thereby presented a weight enhancement, particularly for the weaker hitters who use the low swing-weight clubs.
When the composite shaft was developed, it provided an option for some golfers to switch from a club with the heavier metal shaft to a club with the lighter composite shaft if the golfer experienced improved play with the lighter club. Also, with the lighter composite club, the weight of the club head could be increased slightly whereby the speed of the head is increased which translates into increases in ball speed and distance thereby further enhancing the golfers playing of the game.
With the realization and recognition that the above-noted advantages can be attained by using the lighter composite clubs, there is a need to develop even lighter clubs to provide further enhancement of the playing of the game by golfers.